Twenty improvements that would motivate me to upgrade my 4100:
1. Skid-steer style quick attach on loader
2. Aux hydraulic circuit plumbed on loader to actually run skid-steer attachments.
3. Increased loader capacity to actually be able to lift a full bucket out of a loose sand pile, much less breakout packed clay while digging.
4. Increase loader roll-back. I would sacrafice dump angle for this.
5. Add auto-leveling for use with forks.
6. Sloped hood. Not for aero-dynamics, but for visbility.
7. Built-in frame mount for backhoe.
8. Backhoe mount to not interfere or depend on MMM being removed. Very important for those quick little chores that should only take 15 minutes to dig a little hole and plant a tree or replace the mailbox or whatever.
9. Improved parking brake holding power.
10. Improved design of any plastic parts. Avoid thin sections! I would rather have a few sink marks in the plastic then to have the thin little section around the 3-point control lever crack and flop around. Learn from the toy people - Fisher Price. They use 1/2" wall thickness in a lot of their stuff!
11. Improve the bracket that holds the hyd hoses out of the front tire. Mine fell off. In college, they tought us in Mech. Engineering 101 that one or two screws are a waste of money - might as well not even bolt it on with one screw because it IS GOING TO FALL OFF!
12. Slight increase in loader dig depth. As loader gets older and the mount gets loose, when trying to grade or scrape uneven surfaces, a few more inches of depth would be nice.
13. Soft cab option.
14. Factory tooth-bar option.
15. Lower or third gear range on HST. In some situations, I run out of torque before running out of traction.
16. Cup holder, carry-rack, toolbox, good place to store a rag.
17. Better rust-proofing/paint. Many tractors are not parked indoors.
18. Use a standard 2" receiver for the drawbar.
19. Places on the frame (loops, holes, etc) for transport tie-down (especially in the rear).
20. Keep weight down for mowing.